Collapsible screw-threading tap.



No. 662,361. Patented Nov. 20,1000.

s. B. LEIDY.

COLLAPSIBLE SCREW TIIREADING TAP.

(No Model.) 2 Shee'ts-Sheet I.

l Q' l ll (l,

|i|||||||||||||||||Ulllimmmlulllmm No, 662,361. Patented uw. 2o, |960.

lS. B'. LEIDY. CDLLAPSIBLE SCREW THREADING TAP.

v (Application tiled Apr. 25. 1900.) (No Model.)

2` Sheets-Sheet 2.

IINTTED STATES rrrcn.

PATENT THE ENTERPRISE MANUFACTURING COMPANY OF PENNSYLVANIA- OF SAME PLACE.

ooLLAPslBLE SCREW-THREADING TAP.-

SPECIFICATION fOlHlIlg palt Of Letters Patent NIO, 662,361, dted NOVeIIlbe'r 20, 19.

Application filed April 25 1900. Serial No. 141329. (No model.)

To ctZZ whom, t may concern:

Be it known that I, SYLVESTER B. LEIDY, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Collapsible Screw- Threading Taps, of which the following is a specification.

The object of my invention is to construct a tap for cutting internal threads, so that after the article is threaded the cutters of the tap can be retracted to allow the tap to be immediately Withdrawn from the article or the article moved away from the tap.

In the accompanying drawings, Figure l is an inverted plan view of my improved collapsible tap. Fig. 2 is an end view. Fig. 3 is a longitudinal sectional View showing the cutters projected. Fig. 4c is a view similar to Fig. 3, showing the cutters retracted. Figs. 5, 6, and 7 are perspective views illustrating details of the invention, and Fig. 8 is a diagram view illustrating the action of the trigger.

A is the body of the tap, having a shank a arranged to be coupled to any suitable tap ping-machine. The bodyis hollow,and mounted in the hollow body is a plunger B, having a tapered head b, which projects the cutters and holds them in the projected position during the tapping operation.

Pivoted to the body A at c are three or more levers C. Carried by each lever is a cutter D, of the form clearlyillustrated in Fig. 5. This cutter has the teeth, as shown, and a beveled rear edge, which is preferably on the same bevel as the head b of the plunger B. The cutter is secured to the lever C by a conningscrew d, and in order to prevent it from turning on the lever the cutter has a channel d', into which projects a portion c of the lever C, so that the strain is taken off the bolt CZ. Each lever C has a rear projection c2, and arranged in a socket al in the body A is a spring e. This spring is arranged in a thirnble ft2 in the body, and carried by the spring is a head e2, which bears against the under side of the arm c2 of the lever C. The springs tend to force the cutters toward the center and in contact with the tapered head b of the plunger B, so that as soon as the plunger is withdrawn the springs retract the cutters.

A is a collar secured to the end of the body A by means of a screw 0.3. This collar prevents springing of the head, which is cut away to allow for the free movement of the levers C.

Arranged to slide on the bodyA is .a sleeve E. This sleeve has a threaded portionf, and on the threaded portion are the screw-collars E E.

B is a pin extending through the plunger B and also through slots g g in the body A and through slotsf' in the sleeve. The pin B extends into the space between the collars E, so that on adjusting these collars on the threaded portion of the sleeve Ethe position of the sleeve F in respect to the plunger B can be altered, so as to adjust the plunger in respect to the cutters.

Mounted within the body A is a spring G, which is secured to a pin g' at the rear end and to the plungerB at its forward end. This spring tends to retract the plunger and also to retract the sleeve E, to which it is connected.

Pivoted to sleeve F at t' is a trigger I, having two arms fi 712, the arm vl' being undercut at 3.

71, is a spring bearing against the arm 7l of the trigger I, so as to keep the trigger in the position illustrated in Fig. l.

Bearing against the end of the arm t" of the trigger I is a pusher J, Fig. 8, attached to the machine to which the tap is secured, and the trigger is released from the pusher when the arm 2 strikes a stop K on the fixed portion of the machine, so that as soon as the trigger is released the sleeve E is released from the control of the pusher and the spring G withdraws the plunger and its sleeve and allows the cutters to be reciprocated, so that by setting the stop K at any point a thread can be cut of any desired length. When the pusher J returns, the spring h forces the arm fi of the trigger I again in front of the pusher, so that its plunger B can be moved forward to project the cutters when it is desired to cut another thread.

Thus it will be seen that I am enabled to provide 4a substantial collapsible tap which will cut the threads accurately and quickly and of any length desired within the limit of the tool, and the tap can be adjusted to any IOO automatic tool which has a given motion and to which the Aarticles to be threaded are fed to v the tapping mechanism by automatic means.

I claim as my invention- I l. 'I he combination of the body, pivoted levers, cutters carried thereby, a plung'g'er having a head acting to project the cutters, a

spring tending to retract the plunger, a sleeve coupled to the plunger, and mechanism on the sleeve actuated by operating mechanism `on the machine to force the plunger forward to project the cutters, substantially as described.

2. The combination of the body, cutters carried thereby, a plunger arranged to project the cutters, a spring for retiacti'ng th'e plunger, a sleeve on the shank connected to the plunger, and means for 'adjusting thersleeve in respect tothe plunger, substantially as 'dei z scribed.

3. The lcombina'tion of a body, 'cutters carried thereby, a plunger having a head actin-g Q to project -the cutters, Ya sleevefa pin carried bythe plunger and projecting lthrough slots ters, a plunger for projecting the cutters, a

sleeve connected to the plunger, a trigger vpiv- .ted to the sleeve vand having t'wo arms, 'ai

. pusher and a stop, one arm Vot' the trigger receiving the thrust of the pushenand the other arranged to come in contact with the stop and trip the trigger so as to free it from the pusher, substantially as described.

5. The combination of a body, cutters carried by the body, a plunger Within the body arranged to project the cutters, a sleeve connected to the plunger, 'a trigger pi'voted to the sleeve having two arms, one of said arms beinfg undercut, a pusher'and a stop, the undercut arm of the trigger taking the thrust of the pusher, a spring tending to keep the arm in line with the pusher, the other arm being in linevwith the stop,whereby it is tripped so as vto withdraw 'the trigger from the pusher, substantially as described. y 1 l 6. The combinatie-n in acollapsible tap, of -a body having a collar -ifntegral therewith, le-

vvers pivoted in recesses in said collar, cutters on said levers, a plunger within the ibody having fa head acting to project 'the cutters and to hold them in the p'rojelctle'd position, and a loose sleeve on the outside of theshaft opera'tively and adj'u'stably' connected to said plunger, lsubst'antially fas described.

In testimony whereof I ha'v'e signed in y name to Athis "specification in the presence "of two subscribing witnesses.

SYLVESTER B. LEIDY.

Witnesses MURRAYC. BOYER, JOS. KLEIN. 

